How can P&R facilities contribute to reduced emissions of greenhouse gases?

In this paper we investigate how various properties of Park & Ride (P&R) facilities affect their effects on traffic volumes and greenhouse gas (GHG) emissions. We found that if a P&R is located in an area where it stimulates urban sprawl, regional enlargement or induced traffic, it will not reduce vehicle kilometres travelled. In urban regions without such potential, those P&Rs that intercept journeys by car close to its starting point and transfer travellers to a relatively long public transport ride, contribute the most to reduced GHG emissions. This may be counteracted by increased traffic volumes if the P&R occupy a site which has an alternative use that can contribute to less transport demand and traffic, or if the P&R site stimulates to car journeys replacing travelling by foot, bicycling or public transport to the station. Based on our findings, we developed guidelines for planners and decision-makers for analysing traffic-reducing effects of P&R in the planning and decision processes. This also includes discussions on which measures can be applied instead of constructing new or expanding existing P&R facilities in different contexts.